Thomas Telford Publishing, London, vol 157, pp 229–238 In: Proceedings of the transportation geotechnics symposium, NottinghamĪllenby D, Ropkins JW (2004) The use of jacked-box tunnelling under a live motorway. American Society of Civil Engineers, Reston, Virginia, USA, pp 21–38Īllenby D, Ropkins JW (2003) Geotechnical aspects of large section jacked box tunnels. In: Proceedings of the sessions of Geo-Congress 98, Special Publication No 87. Ropkins JW (1998) Jacked box tunnel design and construction. Tunn Undergr Space Technol 49:320–327Ĭlarkson TE, Ropkins JW (1977) Pipe-jacking applied to large structures. Saeid RD, Elnaz SI (2015) Maximum surface settlement based classification of shallow tunnels in soft ground. Singh K, Prasad P, Mathur S, Gangopadhyay S, Azad F (2012) Indian patent on, stepwise vertical De-stabilization and stabilisation of compacted sandy soil for construction of rail underpass, Patent No. Liao SM, Liu JH, Wang RL, Li ZM (2009) Shield tunneling and environment protection in Shanghai soft ground. Vorster TE, Klar A, Soga K, Mair RJ (2005) Estimating the effects of tunneling on existing pipelines. Melis M, Medina L, Rodríguez J (2002) Prediction and analysis of subsidence induced by shield tunneling in the Madrid metro extension. The study shows that if, overburden soil is reinforced with nails prior to the driving of box tunnel, the chances of collapse or lateral displacement at box tunnel face soil can be minimized for construction of shallow underpass. Further, there was also a gain in load carrying capacity of soil in case of reinforced overburden soil. The lateral displacement of soil at tunnel face was found reduced from 6.92 mm in case of ‘without nailed’ to 0.23 mm in case of ‘with nailed’ overburden soil. To restrict the excessive lateral displacement, the overburden soil above the box tunnel was reinforced with 8 mm diameter tor steel nails prior to pushing of box tunnel. Three vertical offsets from top of soil surface as well as three horizontal offsets from center of loading.
This tunnel was slowly pushed into the soil mass with the help of jack. A steel tank of size 450 mm × 300 mm × 300 mm, filled with cohesionless soil was used, in which a square steel box tunnel of size 34 mm × 34 mm (inner) with 1 mm wall thickness was moved through jacks. In order to overcome this problem, a laboratory model study has been conducted. During the driving of shallow box tunnel underpass, the overburden cohesionless soil experiences large stresses and excessive lateral displacements at the box tunnel face, which sometime causes an accident leading to loss of lives. The construction of shallow box tunnel underpass below rail/road traffic using jack pushing has become a quite common technique these days to create an uninterrupted flow of traffic in metropolitan cities.